This invention relates to a fully-automatic welding device, provided with a manipulator and a quality monitoring mechanism used to monitor the quality of a melted joint, for melting and joining metals together by a welding arc, and this invention relates to a welding skill training device capable of presenting a welding working condition and capable of displaying a welded-joint section operation result and a welded-joint surface operation result based on the welding working condition.
Conventionally, a finish-visual-evaluation system for a welded joint can be classified into three evaluation types, i.e., a pre-welding evaluation, an in-welding evaluation, and a post-welding evaluation from the temporal viewpoint of evaluation execution, and, when evaluated, the in-welding evaluation and the post-welding evaluation in each of which a real object to be welded is used have been employed in most cases.
With regard to the pre-welding evaluation, there is a method disclosed in Japanese Patent Publication No. Hei-7-47209 in which a plurality of welding parameters are stored, thereafter other welding parameters are sequentially determined according to a plurality of condition generating rules, and a welding condition, which is required when welding, is determined by repeating this, and a method disclosed in Japanese Unexamined Patent Publication No. Hei-5-57436 in which only welding conditions that correspond to predetermined conditions are stored in a database, a welding condition that agrees with a predetermined condition that has been input is thereafter retrieved from the database, and, if the welding condition is not contained in the database, the welding condition is inferred by the use of a welding-condition-data-inferring portion constructed by a neural network, and, if welding conditions are suitable, all welding conditions employed at that time are registered in the database.
However, the conventional finish-visual-evaluation system for a welded joint is at a disadvantage in the fact that the quality of a welded-joint appearance cannot be evaluated at any time since member generation occurs in a to-be-welded object because of the in-welding evaluation or the post-welding evaluation and since a welder who has considerable skills is required in the work schedule. Another disadvantage is the fact that a welding result cannot be represented in the form of a graphic figure even if a recommended welding condition is presented in the case of the pre-welding evaluation.
Additionally, in order to acquire arc-welding skills, a method of offering the skills from a skilled welder has been employed, and on-the-job training has been conducted in most cases.
However, the conventional method of acquiring arc-welding skills has a problem in that a recent decline in the number of skilled welders makes it difficult to offer welding skills to beginning welders who intend to newly master the skills.
A first object of the present invention is to solve the aforementioned problems by means of a technique for judging weld quality for acceptance or rejection by specifying welding conditions and material parameters before welding and displaying the result in diagrams and by means of a fully-automatic welding device incorporating the technique thereinto.
A second object of the present invention is to solve the aforementioned problems by means of a welding skill training device by which a beginning welder can confirm the predicted cross-sectional shape of a welded joint that depends on a welding condition any number of times and for which a technique for realizing training equal to an offer of skills from a skilled welder is incorporated.
In order to achieve the first object, the automatic welding device of the present invention has an optimal welding condition operation means for setting information regarding a to-be-welded object that includes board thickness, outer dimensions, and the joint shape of the to-be-welded object and performing arithmetical operations for welding conditions that include welding current, welding voltage, and welding speed suitable for information, whereby the present invention is characterized in that the automatic welding device includes a temperature distribution operation means for performing arithmetical operations for a temperature distribution in a joint of the to-be-welded object from the information regarding the to-be-welded object and from the welding conditions; a temperature distribution operation result recording means for recording at least information regarding the to-be-welded object, the welding conditions, and a temperature distribution operation result calculated by the temperature distribution operation means; a weld penetration display means for displaying at least a penetration width, a penetration depth, and a penetration shape based on the temperature distribution operation result; a bead surface shape operation means for performing arithmetical operations for a molten-metal bead surface shape from at least information regarding the to-be-welded object recorded in the temperature distribution operation result recording means, the welding conditions, and the temperature distribution operation result; a bead surface shape operation result recording means for recording a molten-metal bead surface shape operation result calculated by the bead surface shape operation means; a bead surface shape operation result display means for displaying the surface shape operation result calculated by the bead surface shape operation means by at least a cross-sectional view, a longitudinal sectional view, and a general view of the welded joint; a bead shape observation position setting means capable of setting a bead shape observation position by a viewing point from an arbitrary position in displaying the bead surface shape; an arbitrary position bead shape display means for displaying at least the general view of the welded joint from a position set by the bead shape observation position setting means; a joint quality acceptance/rejection judging means for judging acceptance or rejection of a joint quality of the to-be-welded object from a temperature distribution in the joint of the to-be-welded object in the temperature distribution operation result recording means; a weld starting means for automatically starting to weld the to-be-welded object under the welding conditions recorded in the temperature distribution operation result recording means when judgment of the acceptance of the joint quality is made in the joint quality acceptance/rejection judging means; a welding condition correction means for correcting the welding conditions of at least the welding current, the welding voltage, and the welding speed to satisfy acceptance criteria when judgment of the rejection of the joint quality is made in the joint quality acceptance/rejection judging means; an operation result record situation judging means for judging the presence or absence of similar information regarding the to-be-welded object, a similar temperature distribution operation result record, and a similar bead surface shape operation result record before setting the information regarding the to-be-welded object; and an operation time omitting means for omitting time required for operation by the temperature distribution operation means and time required for operation by the bead surface shape operation means by allowing the weld penetration display means to display a temperature distribution operation result record in the joint of the to-be-welded object and by allowing the bead surface shape display means to display a bead surface shape operation result record when the operation result record situation judging means judges that there is an arithmetical operation record in the past.
In order to achieve the second object, the welding skill training device of the present invention has a welding condition setting means for setting information regarding a to-be-welded object that includes board thickness, outer dimensions, and the joint shape of the to-be-welded object and presenting welding conditions that include welding current, welding voltage, welding speed, and torch angle suitable for information, whereby the present invention is characterized in that the welding skill training device includes a temperature distribution operation means for performing arithmetical operations on a temperature distribution in a joint of the to-be-welded object from information regarding the to-be-welded object and from the welding conditions; a bead surface shape operation means for performing arithmetical operations on a molten-metal bead surface shape from the information regarding the to-be-welded object, from the welding conditions, and from the temperature distribution operation result; a bead shape display means for displaying a welded-joint bead shape by a cross-sectional view, a longitudinal sectional view, and a general view from a surface shape operation result calculated by the surface shape operation means and a temperature distribution calculated by the temperature distribution operation means; a bead shape observation position setting means capable of setting a bead shape observation position by a viewing point from an arbitrary position in displaying the bead shape; and a welding-condition changing means for changing at least a penetration width, a penetration depth, and a penetration shape based on the temperature distribution operation result.